The international technology Group and specialty glass expert SCHOTT offers a safety-critical component for supplying LNG pumps with power: SCHOTT Eternaloc™ terminal headers. They serve as the hermetic feedthroughs for the three-phase electrical power and for the control and instrumentation measurement signals needed to safely and steadily operate LNG pumps and turbine expanders. They must also be durable and robust in order to reliably maintain the pressure integrity of the LNG containment vessel, even in the event of an accident. Based on high-tech glass-to-metal sealing technology, SCHOTT Eternaloc™ feedthroughs are used in more than 6,000 LNG applications worldwide, including the Prelude FPSO (floating production, storage and offloading unit) currently under construction in Korea.

SCHOTT has been a partner to the LNG industry since 1985, supplying more than 6,000 terminal headers to on- and offshore LNG applications worldwide. Source: SCHOTT.

The success of LNG transportation and storage depends on the reliability of all safety-related components – even the small ones. SCHOTT has been a partner to the LNG industry since 1985, supplying more than 6,000 terminal headers to on- and offshore LNG applications worldwide, including the Prelude FPSO which is currently being built in Korea. “All 6,000 headers are still performing maintenance-free,” states Thomas Fink, General Manager of the Nuclear Safety Division at SCHOTT Electronic Packaging. “The Korean LNG vessel building industry is in the lead worldwide. Korea represents an important market for us: For example, the LNG terminals Samcheok, Tongyeong and Pyeongtaek also rely on our feedthroughs. We offer products which help to raise the safety and reliability of LNG-related equipment. The outstanding performance record of our terminal headers is our proof-point,” he says.

The extreme operating environment of high gas pressure and temperatures of -162°C places tremendous stress on terminal headers. Yet in event of an accident, the seals of these electrical connections must remain absolutely leak tight. Reliability of the seals could potentially be the weak point of the entire system. Other feedthroughs that use epoxy or ceramic sealing materials have technological disadvantages which could result in leakage and electrical malfunction.

SCHOTT Eternaloc™ terminal headers are manufactured using proven glass-to-metal sealing technology. Glass has great inherent strength – unlike its reputation of fragility, the compressive strength of glass is ten to twenty times higher than its tensile strength. By using exterior metal housings with a much higher coefficient of thermal expansion than glass, the housing shrinks firmly onto the glass during the cooling process. Sealing glass directly to the metal housing, without any welding or soldering required, creates a robust, compressive seal that is highly resilient to mechanical stress, high pressure and temperature cycling.

Inorganic and chemically inert, glass seals are also non-aging and resistant to aggressive and potentially corrosive media. Hence, Eternaloc™ terminal headers are maintenance-free, and reduce the total cost of ownership for owners and operators.

SCHOTT’s electrical feedthroughs are certified according to specific local regulations such as KOSHA (Korea Occupational Safety and Health Agency) for Korea, the international IEC standard for electrical safety (IECEx) as well as the European ATEX standard. These directives pertain to security-relevant requirements for the use of devices and equipment under the most severe conditions.

Background information on SCHOTT’s glass-to-metal sealing technology:
Glass-to-metal sealing technology is also the proven and standard technology in other safety-critical and harsh-environment applications: for example, glass-to-metal sealed feedthroughs by SCHOTT reliably pass temperature, vibration and motor speed measurements through the pressure vessel of a hydrogen-cooled generator.

SCHOTT also has more than 60 years of experience in supplying electrical penetrations for use in nuclear power plants, where the glass-to-metal sealed assemblies provide a leak-tight pass-through for power cables through the containment structure.

About SCHOTT
SCHOTT is an international technology group with 130 years of experience in the areas of specialty glasses and materials and advanced technologies. SCHOTT ranks number one in the world with many of its products. Its core markets are the household appliance, pharmaceutical, electronics, optics and transportation industries. The company is strongly committed to contributing to its customers’ success and making SCHOTT an important part of people’s lives with high-quality products and intelligent solutions. SCHOTT is committed to managing its business in a sustainable manner and supporting its employees, society and the environment. The SCHOTT Group maintains close proximity to its customers with manufacturing and sales units in 35 countries. Its workforce of 15,400 employees generated worldwide sales of US$2.5 for the 2012/2013 fiscal year.

Terminal headers serve as the hermetic feedthroughs for three-phase electrical power, as well as control and instrumentation signals in submerged LNG pumps, turbine expanders and compressors. Source: SCHOTT.